Sphingosine kinases (SphK) 3 are prototypical members of a highly conserved family of
signaling enzymes. They are present in organisms as diverse as mammals, flies, worms,
yeast, and plants and catalyze the phosphorylation of sphingosine to form the bioactive
sphingolipid metabolite sphingosine 1-phosphate (S1P). Two distinct mammalian isoforms
have been identified, SphK1 and SphK2. Other close relatives, ceramide kinase (CerK) and
the more promiscuous acylglycerol kinase (AGK), are now emerging as lipid-signaling …